Next Permutation

import java.util.* ;
import java.io.*; 
import java.util.ArrayList;
import java.util.Collections;

public class Solution 
{
	public static ArrayList<Integer> nextPermutation(ArrayList<Integer> permutation) 
	{
		// Write your code here.
		int k=permutation.size();
		int nums[]=new int[k];
		for(int i=0;i<k;i++)
		{
			nums[i]=permutation.get(i);
		}
		 int i=nums.length-2;
        int j=0;
        while(i>=0 && nums[i]>=nums[i+1])
        i--;
        if(i>=0)
        {
               j=nums.length-1;
                while(nums[j]<=nums[i])
                j--;
                swap(nums,i,j);
        }
        reverse(nums,i+1,nums.length-1);
		for(int l=0;l<k;l++)
		{
			permutation.set(l,nums[l]);
		}
			return permutation;
    }
    static void swap(int nums[],int i,int j)
    {
        int temp=nums[i];
        nums[i]=nums[j];
        nums[j]=temp;
    }
    static void reverse(int nums[],int i,int j)
    {
        while(i<j)
        {
            swap(nums,i,j);
            i++;
            j--;
        }
    }
	}